The young surfers showed their grit and courage in maxing Zippers.
Crosby makes it two Los Cabos Open of Surf victories for the Colapinto family after his brother, Griffin, won in 2016.
With his win, the San Clemente, California, native followed in the footsteps of his older brother in pumping conditions in Los Cabos.
Another big day witnessed all women's action with the top seeds debuting in the QS6,000 and the women's Pro Junior beginning.
The women's Qualifying Series and North America Junior Tour set its eyes on Cabos June 6 - 11.